Gear timing method



H. W. SEMAR GEAR TIMING METHOD July 30, 1946.

4 Sheets-Sheet 1 Filed April 14, 1943 (1/, W? IM ATTORNEY July 30, 194-6. H; w, SEMAR 2,404,865

GEAR TIMING METHOD F iled April 14, 1945 4 Sheets-Sheet 2 INVENTOR HHROLD W. EEMRR.

BY wmalm ATTORNEY Fla. 3.

July 30, 1946. H. w. SEMAR 2,404,355.

GEAR TIMING METHOD 7 Filed April 14, 1945 j 4 Sheets-Sheet 3 "WENTOR WITNESSES: as

, HRROLD W. SEMRR- BY Wp-M 16 7 'M I ATTORNEY July 30, 1946. H. w. SEMAR 2,404,365

GEAR TIMING METHOD Filed April 14, 1945 4 Sheets-Sheet 4 INVENTOR HRR OLD W. SEMRRJ (MW, Rum;

ATTORNEY Patented July 30, 1946 GEAR TIIVIING METHOD- Harold W. Semar, Drexel Hill, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application April 14, 1943, Serial No. 482,977

3 Claims.

invention relates to gearing, more particularly to reduction gearing of the locked-train type, and it has for an object to provide an improved method of dividing between the two highspeed gears, the torque delivered thereto by the highespeed pinion.

Another object of the invention is to provide improved method for obtaining equal division, between the high-speed gears of a locked-train reduction gear assembly, of the torque delivered thereto by the high-speed pinion.

Thes and other objects are effected by the invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of thisapplication, in which:

Fig. 1 is an end view of a reduction gear assembly such as might be used in ship propulsion for" driving from two sources of power to single powershaft, together with the apparatus involved in this invention for dividing between the two high-speed gears, the torque delivered thereto by the high-speed pinion;

'Fig. 2 is a sectional viewtaken along the line II-II of Fig. 1,.100king in the direction indicated by the arrows;

Figs. 3 and 4 are similar diagrammatic views illustrating the difference in. application of the apparatus for adjusting the torque in the lefthand gear train (Fig. 3) and the right-hand gear train (Fig.4);

Fig, 5 is a front elevationai viewof a torquing jig and associated apparatus for performing one step of the invention covered by this application;

Fig. 6 is a transverse sectional view taken along the line VI-VI of' Fig. 5, looking in-the direction indicated by the arrows;

Fig. '7 is a sectional View taken alon the line VII-VII of Fig. 6, looking in the direction indi-- cated 'by the arrows;

Fig. 8 is a fragmentary view of a portion of the structure of Figs. 5, 6 and 7;

Fig. 9 is a transverse sectional view taken through a piece of apparatus involved in the performance of the method herein disclosed;

Fig. 10 is a transverse sectionalview taken along the line X-X of Fig. 9', looking in the direction indicated by the arrows;

Fig. 1.1 is an enlarged fragmentary view of a portion of. the apparatus shown in Figs. 9 and 10;

Fig. 12 is a transverse sectional view of a por-' tion. of the apparatus shown. in. Figs. 8 and. 9 with.

certain parts removed andv replaced by others;

Fig. 13 is a sectional View taken. along the line 2 XIII-XIII' of Fig. 12, looking in the direction indicated by the arrows; and

Fig. 14 is an enlarged fragmentary view of a portion of the apparatus shown in Figs. 12 and 13.

In gears of the locked-train. type, where the drivin torque from the high-speed. pinion .is transmitted to two high-speed gears, the division of torque between. these two gears depends upon the angular relation of the latter. In; order that equalv torques may betransmitted to each gear, the angular relationship thereof must be accurately set at the time of assembly of the gear train. This setting 'must take into account the backlash in the teeth of allygears'and couplings, all bearing clearances and all strains in the stressed parts of the gear train.

These factors can best be takenv into account by actually applying torque sufficient to liftall rotating parts into their running positions and to take up all baeklashes. With torque thusapplied, the angular relation. between any two ad.- joining. elements can. be determined and/or set at any predetermined angle. 7

In order to. clearly disclose the novelieatures of the subject invention-the same has beenillustrated as applied to conventionalreduction' gearing of the locked-train type asis frequently used in. the propulsionequipment oi vessels, where twosources of. power,.for example, the high-pressure turbine and the low-pressure turbinedrive throughtwo trains of reductiongearin to: asingle propellershaft InFigs. 1,. 3 and. 4, the two trains are indicated as A. andv B, it being assumed that the A transmits power from the highepressure turbine and. train 3 from the lower-pressure turbine, to drive a single propeller shaft 34 (Fig. 1).

Inasmuch as the two trains of gearing are similar, it is believed that a description of one train will. be sufiicient to fullydi'sclose the presentiimvention, and hence the following description is given of train A.

This train comprises ahigh-speed pinion shaft hollow shaft #5, by suitable means, such as the bolts 24.

The coupling sleeve is provided with internal teeth adapted to mesh with external teeth 21 provided on the coupling hub 28, secured to the end of the quill shaft 29 by a suitable means, such as keys 30.

The other 'enfd'fof the'qui1l shaft 29' is secured" to the hollow shaft ISby keys 3!, the shaft 19 being rotatably supported by the bearings 32, likewise carried by the frame ll.

Mounted on each hollow shaft I9 is a low speed pinion 20, these pinions both meshing with a sin- 224047865 L WII? in spaced-apart relation upon a rod 64. Movement of the lower block 52 toward the adjacent end of the'rod E4 is limited by the nut 65 threaded gle low speed, or bull gear 33,-keyed to the main shaft 34, which either carries the propelleror'iis coupled to the propeller shaft. The entire" gear assembly is enclosed by suitable casing structure, indicated at 35.

In performing the method of the present inven tion, the gear trains are completely assembled with-the exception of the coupling hub 28 of the upper quill shaft of-each train. In place of the omitted coupling hubs the torque-measuring apparatu'sg disclosed in'F'igs. 5,.6 sand 7,.is inserted.

'I hisapparatus comprises a torquing hub 40 on which is rotatablymounted a torquing sleeve 4|. The torquing hub is rabbeted at 42 to receive the corresponding internal rib or flange 43 formed on the torquing sleeve ll, and the two parts are retained'in assembled relation by a segmental retaim'ng ring 44, fitting into a mating groove 45 formed in the rabbeted surface 42 of the torquing hub 40, the retaining ring being secured to'the torquing sleeveby suitable means, such as the bolts. 1

The torquing sleeve 4! is provided with external teetnds corresponding to the teeth 21 of the coupling hub for which this apparatus is substituted, the teeth 48 being adapted to mesh with the internal' teeth 26 on the couplingsleeve 2!. The torquingv hub 4.0 is provided with keyways 49 adapted to'cooperate withthe keyways 50 of the quill shaft to receive temporarykeys 5!, locking the torque. hub-t0 the quill shaft. Thus, it will be seen that the ftorquing hub 40 may. receive or transmit tor'queifrom or to the quill shaft 29 and the torquin'gisleeve .4 l lmay receive or transmit torque from onto the couplingsleeve 2|. At. the same time,

the .ztorquing sleeveand torquing hub are rotat-' a'ble relative to "eachother.

'1 In; order thatthe relative angular position of the torquing sleeve and torquing hub may be determined, the formeris providedwith aradiallyextending pin 52 and the latter with a similar pin 53,.there being provided an opening 54 in the torquing sleeve through which the pin 53 extends, the opening54 being of sufficientcircumfere'ntial extent to permit of the necessary relative movement of the torquing sleeve and torquing hub, Without contact of the pin 53 with the end walls of the o-pening 54. The distance between or across the heads of the pins 52 and 53 may be accurately measuredby a micrometerin order to determine the exact angular relationship of the torquing sleeveandtorquing hub at anytime.

To'resist relative rotation of the torquing sleeve andjto'r'quing hub, in order that the entire gear trainmay be subjected tosufiicient torque to take upplay in the bearings and backlash of the teeth,

thereisprovided a torquing jig 5| adapted to cooperate with the torquing sleeve and torquing hub in the manner to be immediately described.

The torquing-hub is' provided at its outer or free end with apairof opposed enlarged portions 56. and the::torquing" sleeve has similar portionsi on that end of'therod. The other end of the rod is "surrounded by a, compression spring 66, re-

"strained between the washer 61 resting against the nut 68 on the rod 64, and the upper block 63,

with the result that the blocks 62 and 63 are i normally urged toward each other by the spring 66. The upper block 63 carries a pair of link members 10 and H pivotally connected thereto at one end bypins 12 extending through the links and the block, and retained by cotter pins .13. The free ends of the link members 10 and H are concaved, at M, to engage with the shanksof the abutment pins 58 and 59 (Fig. 5). block 62 is providedwith similar link members 16 and H, pivotally connectedthereto by pins 18 having concaved ends engaging the pin-abutments 58 and 59.

In order to prevent buckling of the rod 64 of the torquing jig 6|, there is provided a restraining frame 80 secured to the torquing hubby suitable'means such as the screws 8|.

' 1:. It will be apparent that the compressive stresses 7 tend to. rotate the torquing. hub 40 clockwise.

With the torquing'sleeve and torquing hub thus torqued, torque may be applied to the high-speed pinion, with the low-speed gear restrainedfrom rotating sufficient to lift allthe parts into their running positions and to eliminate backlash, as.

will be hereinafter described.

.1 In order to apply a measured torque'to the entire gear train, there is. provided a further torquing apparatus, indicated generally at 89, for.

applying torque to the high-speed pinion andfor preventing rotation of thelow-speed gear." As best shown in Fig. 1, this apparatus comprises a pair of torquing arms and 9|, the arm 90 being secured to the shaft carrying the high-speed pinion of train A, by suitablemeans, such as bolts 92. In like manner, the arm BI is secured to the shaft carrying the high-speed pinion of the train B, by similar bolts 92; The free ends of the arms 99 and 9! are connected by a rod-93, :one end of V which extends slidably through a block 94, preferably supported between a pair of ears 95, carried by the arm 90. This end of the rod 93 is threaded,

asat 96, and carries an adjustingnut 9'l for in-} creasing ordecreasing the effective length of the rod93.

The, jothjer end of the rod is fixedly s'ec'auredv to""a"plate"'99, slidablyfmounted on a pair of spaced rods I00, supported by a block. l0l,"con-" nected by a pair of ears I02 andpin I03 to'the free end of the torquing arm 9|. A plate I04 ls slidably-mounted on the pair of rods I00, at the opposite side of the plate "99 from the block ml. The rods I00 have threaded terminal portions 1 extendingthrough'the plate 104' and carryingad- The lower.

justing nuts I05 for moving the plate Hi4 toward or away from the block lfll' to vary the compression of spring I86, disposed between said plate i 4 and the plate 99 in which th end of the rod 93 is secured. Thus, it will be apparent that the compression spring H36 tends to urge thefree ends of the torquing arms 90 and 9| toward each other. 1

In Figs. 9 to 13 there is illustrated apparatus for performing a further step in the process herein disclosed. This apparatus comprises a base plate 85', to which may b bolted the coupling sl'eeveZl or a suitable sleeve having similar internal teeth. A dummy quill shaft 85 isrnounted on the base plate 85, in concentric relation to the coupling sleeve 2 i, and' is retained in position by the stud 8! andnut 88. Thus, there is provided between, the dummy quill shaft and the coupling sleeve an annular space for reception of the torquing hub 48 and torquing sleeve 41 in their assembled relation. (Figs. 9 and 10.)

The torquing apparatus hereinbefore described is used inthe following manner to provide for equal division, between the two high-speed gears, of the torque from the high-speed pinion.

l. The gear trains are completely assembled with the exception of the coupling hubs 28 of the upper quill shafts 29.

2. The torquing hub is placed inside the torquing sleeve and the two substituted for the omitted coupling hub 28 of train A, with the teeth 48 of the torquing sleeve in engagement with the teeth 25 of the coupling sleeve, and with the torquing hub temporarily keyed to the quill shaft 29. (Fi 6.)

3. The torquing jig Si is applied to the torquing sleeve with the link members H and H engaging the abutment pins 58 of the torquing hub and with the links '10 and TI engaging the abutment pins 59 of the torquing sleeve (Fig. 5). V

4. Note is made of the number of the particular tooth 48 on the torquing sleeve which is positioned between the two marked teeth 26 of the coupling sleeve (Fig. 8).

5. The torquing arms 90 and 9! and associated rod and spring structure 93 and H36 are mounted on the high-speed pinion shafts in the manner illustrated in Figs. 1 and 3, assuming that the torquing jig 6| hasbeen applied to the gear train A.

6. The springs 66 and I536 are adjusted to the correct compression which can be determined in any conventional way, as will be obvious to those skilled in the art. The torque exerted by spring 66 is made equal to one-half of the total torque that spring I06 exerts on both upper and lower ears.

'7. The gears are rolled in either direction several times by applying force to both of the torquing arms in succession, and the distance between or over the measuring pins 52 and 53 measured with a micrometer or similar suitable instrument. Preferably, the rolling and measuring are repeated several times and the average of the readings taken.

8. The springs 56 and I05 are released, the torquing sleeve and torquing hub removed, but still retained in assembled relation, and the coupling sleeve is removed. If, at this stage, a temporary or dummy sleeve is used, it is unnecessary to remove it. 7

9. The coupling or temporary sleeve is bolted to the temporary base plate 85 concentric with the dummy quill shaft 86, also bolted to the plate 85.

10. The torquing sleeve and torquing hub are assembled on the dummy quill shaft and sleeve. The same numbered tooth on the torquing sleeve, as previously recorded, must be between the two marked teeth of the coupling sleeve, as when previously assembled in the actual gear assembly.

11. The torquing hub is keyed to the dummy quill shaft.

12. The dummy quill shaft and the torquing hub are rotated relative to the torquing sleeve and coupling sleeve until the dimension between or over the measuring pins 52 and 53 correspond to the average measured dimension previously obtained (Step 7).

NOTE.Care should be taken to rotate .the torquing hub and dummy quill shaft in the same direction as when the torque was applied to the assembled gear train, that is, with the teeth in contact on their ahead driving faces, which, in the case of marine propulsion gearing, would be with the apparatus driving ahead.

13.The dummy quill shaft is clamped inthi's position by tightening the nuts 88 on the stud 8T.

14-. The torquing hub and torquing sleeve are removed from the dummy quill shaft and the coupling hub 28 assembled in place thereof be tween the coupling sleeve 2| and the dummy quill shaft 86, the external teeth 21 of the coupling hub engaging the internal teeth 25 of the coupling sleeve. The tooth 27- of the coupling hub, which lies between the two marked teeth 26 of the coupling sleeve, is provided with a corresponding mark so that it may always be assembled in the same relation thereto. (Fig. 14.)

15. Keyways are scribed on the coupling hub in line with the keyways' on thedummy quill shaft.

16. The coupling hub is removed and keyways formed therein at the locations indicated by the scribe marks.

17. The coupling hub and coupling sleeve are removed from the base plate and reassembled in the gear train, the coupling flange being bolted to the hollow shaft l5 and the coupling hub being keyed to the gear shaft 29.

This completes the operation of equally dividing between the two high-speed gears, the torque transmitted thereto by the high-speed pinion for the gear train A. The same procedure is followed with respect to the train B, except that the torquing arms 90 and SI, the rod 93 and spring mechanism I06 are applied in inverted position in the manner illustrated in Fig. 4:.

While the invention has been shown in but one form, it will be obvious to those. skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and it is desired, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What is claimed is: r

1. In assembling a locked train of double-reduction gearing comprising a high-speed pinion, a pair of high-speed gears carried by a pair of intermediate shafts and driven by said highspeed pinion, a pair of slow-speed pinions carried by said pair of shafts and a slow-speed gear driven by said pair of said slow-speed pinions, the method of dividing equally between the two high-speed gears the torque transmitted thereto by the high-speed pinion; which method comprises assembling the gear train with the exception of a first intermediate element thereof; substituting for said element second and third elements rotatable relative to each other about a common axis; connecting the second element to a fourth element in the gear train and the third element to a fifth element in the gear train; applying equal and opposite torques to said secnd and third elements to rotate them relative to each other about said common axis; applying a torque to the high-speed pinion while the slowspeed gear is restrained from rotating, said torque being sufficient to constrain all rotating parts to assume their running positions with all back lash removed; determining the angular relationship of the fourth and fifth elements; removing the second and third elements; replacing them with the first element for which they were substituted; and so connecting said first element to the fourth and fifth elements that the latter have the determined angular relationship.

2. In assembling a locked train'of double-reduction gearing comprising a high-speed pinion, a pair of high-speed gears carriediby a pair of intermediate shafts and driven by said highspeed pinion, a pair of slow-speed pinions carried by said pair of shafts and a slow-speed gear driven by said pair of said slow-speed pinions,

and quill drives, including coupling hubs and coupling sleeves, between the high-speed gears and the low-speed pinions, the method of dividing equally between the two high-speed gears the torque transmitted thereto by the high-speed pinion, which method comprises; assembling the gear train with the exception of the coupling hub of one of the quill drives; nesting a torquing hub within a torquing sleeve with said torquing hub and torquing sleeve relatively rotatable; substituting the nested torquing hub and torquing sleeve for the omitted coupling hub with the torquing hub mounted on and connected to the adjacent quill shaft and the torquing sleeve mounted in and connected to the adjacent coupling sleeve; applying equal and opposite torques to said torquing hub and said torquing sleeve to rotate them relative to each other; applying a measured torque to the'high-specd pinion while the slow-speed gear is restrained from rotating, said torque being sufficient to constrain all rotating parts to assume their running positions with all backlash removed; ascertaining the angular relationship of the coupling sleeve and the quill shaft; removing the torquing hub and torqu ing sleeve;,replacing them with the coupling hub for which they were substituted; and connecting said coupling hub to the coupling sleeve and quill shaft with said coupling sleeve and quill shaft in the ascertained relative angular relationship.

3. In assembling a locked train of double-reduction gearing comprising a high-speed pinion,

a pair of high-speed gears carried by a pair of intermediate shafts and driven by said highspeed pinion, a pair of slow-speed pinions"car-' ried by said pair of shafts and a slow-speed gear driven by said pair of said slow-speed pinions, and quill drives, including coupling hubs and coupling sleeves, between the high-speed gears and the low-speed pinions, the method of dividing equally between the two high-speed gears the torque transmitted thereto by the high-speed pinion, which method comprises;assembling-the gear train with the exception of the coupling hub of one of the quill drives; assembling a torquing hub within a torquing sleeve with said hub and sleeve relatively rotatable; substituting the assembled torquing hub and torquing sleeve for the omitted coupling; interlocking the torquing sleeve and the coupling sleeve to provide a driving connection therebetween keying the torquing hub to the quill shaft to provide a driving connection therebetween; applying equal and opposite torque to the torquing hub and the torquing sleeve to rotate them relative to each other; applying a torque to the high-speed pinion while the slow-speed gear is restrained from rotating, said last-mentioned torque being sufilcient to constrain all rotating parts to assume their running positions'with all backlash removed; determining the angular relationship of the torquing hub and the torquing sleeve; removing thecoupling sleeve, the torquing sleeve and the torquing hub from the gear train and mounting them in assembled relation about a dummy quill shaft on a temporary support with the coupling sleeve and the torquing sleeve interlocked; securing the coupling sleeve to said temporary support; keying the torquing hub to the dummy quill shaft; rotating the torquing hub and the dummy quill shaft with respect to the torquing sleeve to the relative angular relationship of said torquing hub and torquing sleeve which was" previously determined; securing the dummy quill shaftlto the temporary support; removing the torquing hub and torquing sleeve from the assembly on the temporary support and substituting the coupling hub therefor in interlocking engagement with the coupling sleeve; indicating on the coupling hub the location for a keyway complementary to the keyway in the dummy quill shaft, forming a keyway in the coupling hub at the indicated location; and placing the coupling sleeve and coupling hub in thegear train to complete assembly of the latter.

HAROLD W. SEMAR. 

